Highs and lows

The past year has been a mixed one for research in the addictions. The Global Burden of Disease study confirmed that alcohol was a major contributor to the burden of disease in developed countries, as a risk factor for injury and alcohol dependence (Murray). A 10-year study of 65 171 Kaiser Permanente Medical Care Program members found that regular marijuana use had little impact on mortality (Sidney). Its association with increased AIDS mortality in men, probably suggests that it is a marker for male homosexual behaviour. Reassurance about the mortality risks of marijuana is premature because the mean age at follow-up was only 43 years: cigarette smoking and alcohol use were only modestly associated with premature mortality.

Rapid opiate detoxification treatment

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Food habits of young and middle-aged women living outside the capital cities of Australia

Young (18-22 years) and middle-aged (45-49 years) women living in urban and rural areas of New South Wales completed a brief food frequency questionnaire as part of a wider health survey. Urban women in both age groups consumed meat less frequently than women in rural areas; and women in the less populated rural areas were more likely to eat green and yellow vegetables and least likely to eat dried beans. There were few other geographic differences in food habits. Middle-aged women consumed reduced-fat milk, fruit, vegetables, fish, biscuits and cakes significantly more frequently, and rice, pasta, full-cream milk, fried food and take-away food less frequently than younger women. Smokers in both age groups consumed fresh fruit, vegetables and breakfast cereals significantly less frequently than non-smokers, and women with low levels of habitual physical activity consumed fresh fruit and cereals less frequently than more active women. The findings suggest that strategies aimed at changing eating behaviours should be age-group-specific and targeted specifically to smokers and less active women.

Psychological distress among female sex workers

The prevalence and correlates of psychological distress were examined in a sample of 171 female sex workers in Queensland. It was found that 28 per cent were above the GHQ-28 threshold for mild psychiatric morbidity, a rate that is not appreciably different from that of women in the general community. The sample included only eight street sex workers, all of whom reported significant distress. Logistic regression analyses showed that a history of injecting drug use, an early age at leaving home and wanting to leave the sex industry were independent predictors of poor mental health. Distressed sex workers reported fewer sexual health examinations and less consistent condom use with their clients than those who were not distressed.

Characterization of serum antibodies to Porphyromonas gingivalis in individuals with and without periodontitis

Although Porphyromonas gingivalis is a defined pathogen in periodontal disease, many subjects control the infection without experiencing loss of attachment. Differences in host susceptibility to the disease may be reflected in the pattern of humoral antibodies against specific P. gingivalis antigens. The aim of this study was to determine the presence of antibodies against immunodominant P. gingivalis antigens as well as the isotype and subclass of anti-P. gingivalis antibodies against outer membrane antigens in four groups of patients: P. gingivalis-positive, 1) with and 2) without periodontitis, and P. gingivalis-negative, 3) with and 4) without periodontitis. Antigens of molecular weight 92, 63, and 32 kDa and lipopolysaccharide were found to be immunodominant. Group 1 subjects showed a significantly higher response to the 92 and 63 kDa antigens compared with other groups. The response to lipopolysaccharide was significantly higher in group 1, and lower in group 4 than in groups 2, 3. Immunoglobulin G(1) (IgG(1)), IgG(2) and IgM antibodies against P. gingivalis outer membrane were present in all subjects, while only some subjects were seropositive for IgG(3), IgG(4) and IgA. There were no differences in concentrations for IgG(1), IgG(3) and IgM. The IgG(2) concentration in group 4 was significantly higher than in groups 1 and 2, while the IgG(4) concentration in group 4 was significantly lower than in other groups. The frequency of seropositivity for IgG(4) and IgA was lowest in group 4, while IgG; seropositivity was almost exclusively seen in healthy patients iii groups 2, 4. These findings suggest that the presence of IgG(3) may reflect non-susceptibility to the disease, while lack of IgG(4) may be indicative of periodontal health and lack of infection.

Jobless - Unemployment and young people's health

Morrell, Taylor and Kerr, from the University of Sydney's Department of Public Health, review the evidence of an association between unemployment and psychological and physical ill-health in young people aged 15-24 years. Aggregate data show youth unemployment and youth suicide to be strongly associated Youth unemployment is also associated with psychological symptoms, such as depression and loss of confidence. Effects on physical health have been less extensively studied; however, there is some evidence for an association with raised blood pressure. Finally, the prevalence of lifestyle risk factors (cannabis use and, less consistently tobacco and alcohol consumption) is higher in unemployed compared with employed young people.

Vaccine-induced Th1-type responses are dominant over Th2-type responses in the short term whereas pre-existing Th2 responses are dominant in the longer term

The effect of adjuvant on induction of human papillomavirus type 16 E7 protein-specific cytotoxic T lymphocytes (CTL) and immunoglobulin G (IgG)(2a) antibody was studied in C57BL/6 J mice immunized with various adjuvants and E7 protein. Quil-A adjuvant, but not complete Freund's adjuvant (CFA) or Algammulin, induced a T-helper 1 (Th1)-type response to E7, which was characterized by CTL activity against a tumour cell line transfected with E7 protein and by E7-specific IgG(2a). All tested adjuvants elicited comparable levels of E7-specific IgG(1). The longest duration and greatest magnitude of CTL response was seen following two immunizations with the highest dose of E7 and Quil-A. Simultaneous immunization with a Th1 and a T helper 2 (Th2)-promoting adjuvant gave a Th1-type response. However, E7 and Quil-A were unable to induce a Th1-type response (as measured by the inability to generate anti-E7 IgG(2a) antibody) in animals with a pre-existing Th2-type response to E7. These results suggest that saponin adjuvants may be suitable for immunotherapy in humans where a Th1-type response is sought, provided that there is no pre existing Th2-type response to the antigen.

Observations of QSO J2233-606 in the Southern Hubble Deep Field

The Hubble Deep Field South (HDF-S) Hubble Space Telescope (HST) observations are expected to begin in 1998 October. We present a composite spectrum of the QSO in the HDF-S held covering UV/optical/near-IR wavelengths, obtained by combining data from the Australian National University 2.3 m telescope with STIS on the HST.(1) This intermediate-resolution spectrum covers the range 1600-10000 Angstrom and allows us to derive some basic information on the intervening absorption systems which will be important in planning future higher resolution studies of this QSO. The QSO J2233 - 606 coordinates are alpha = 22(h)33(m)37(s).6, delta = -60 degrees 33'29 (J2000), the magnitude is B = 17.5, and its redshift is z(em) = 2.238, derived by simultaneously fitting several emission lines. The spectral index is alpha = -0.7 +/- 0.1, measured between the Ly alpha and Mg II emission lines. Many absorption systems are present, including systems with metal lines redward of the Ly alpha emission line at z(abs) 2.204, 1.942, 1.870, 1.787 and a few very strong Ly alpha features at z(abs) = 2.077, 1.928, without similarly strong metal lines. There is a conspicuous Lyman limit (LL) absorption system that is most likely associated with the z(abs) = 1.942 system with a neutral hydrogen column density of N-HI = (3.1 +/- 1.0) x 10(17) cm(-2). There is some evidence for the presence of a second LL absorber just to the blue of the conspicuous system at z = 1.870. We have employed a new technique, based on an analysis of the shape of the observed spectrum in the region of the LL absorption, to explore the properties of the gas. We tentatively conclude that this system might have suitable characteristics for measuring the deuterium-to-hydrogen (D/H) ratio.

Targeting of a cholecystokinin-DNA complex to pancreatic cells in vitro and in vivo

The carboxy terminal octapeptide of cholecystokinin (CCK8) is a hormone that binds high affinity receptors in a number of tissues including pancreas and pancreatic tumours. As part of our studies to develop effective gene therapy for the treatment of pancreatic cancers, we have investigated various gene delivery systems that depend on CCK8 receptor targeting. In this paper,we describe the synthesis of a CCK8-DNA complex designed to deliver foreign DNA to cholecystokinin receptor-positive cells. CCK8 was ligated to avidin and then complexed to linearis biotinylated DNA (pSV-CAT). The uptake of P-32-labelled CCK8-DNA complex by rat pancreatic acini was linear with time over 4 h with 65-70% of uptake inhibited by 100 nM CCK8. The complex appeared to be internalised since it could not be removed by acid wash. When administered intra-arterially, the complex was rapidly removed from the circulation with no evidence of targeted delivery to the pancreas, However, following a single intraperitoneal dose, the pancreas accumulated-5- 8% of the total administered complex by 24 h. These results suggest that peptide-dependent gene delivery to CCK receptor positive cells in vivo is feasible but, when administered directly into the circulation, diffusional barriers across the endothelium may limit distribution to peripheral tissues. Intraperitoneal administration therefore may be a useful alternative for targeting the pancreas.

An experimental study of the effects of work stress, work control, and task information on adjustment

The present study was designed to examine the main and interactive effects of task demands, work control, and task information on levels of adjustment. Task demands, work control, and task information were manipulated in an experimental setting where participants completed a letter-sorting activity (N = 128). Indicators of adjustment included measures of positive mood, participants' perceptions of task performance, and task satisfaction. Results of the present study provided some support for the main effects of objective task demands, work control, and task information on levels of adjustment. At the subjective level of analysis, there was some evidence to suggest that work control and task information interacted in their effects on levels of adjustment. There was minimal support for the proposal that work control and task information would buffer the negative effects of task demands on adjustment. There was, however, some evidence to suggest that the stress-buffering role of subjective work control was more marked at high, rather than low, levels of subjective task information.

Methadone maintenance treatment reduces heroin injection in New South Wales prisons

The purpose of this study was to examine whether methadone maintenance treatment reduces injecting risk behaviour land therefore transmission of blood-borne viral infections) among prisoners in New South Wales (NSW), using comparison of retrospective reports of drug use in prisons for people who received standard drug treatment, time-limited methadone treatment and methadone maintenance treatment, The setting for the study was the NSW prison system. One hundred and eighty-five injecting drug users who had been recently released from NSW prisons were recruited in 1993, Self-reported drug use and injecting risk behaviour were compared in inmates who received standard drug treatment (counselling), time-limited methadone treatment and methadone maintenance treatment. HIV status was determined by serology, Intervention comprised high and low dose methadone treatment and counselling. The groups were similar in terms of most basic demographic characteristics but subjects who had been maintained on methadone reported a significantly lower prevalence of heroin injection, syringe sharing and scored lower on an HIV Risk-taking Behavioural Scale than subjects who received standard drug treatment and time-limited methadone treatment, This study suggests that methadone treatment is associated with reduced injecting risk behaviour in prison with adequate (greater than 60 mg) dose and duration in treatment. These treatment conditions are known to increase effectiveness in community-based methadone programmes. Prospective studies are required to evaluate the effectiveness of methadone programmes in the prevention of HIV and other blood-borne viral infections among IDU prisoners.

Calcium-permeable AMPA receptors mediate long-term potentiation in interneurons in the amygdala

Fear conditioning is a paradigm that has been used as a model for emotional learning in animals'. The cellular correlate of fear conditioning is thought to be associative N-methyl-D-aspartate (NMDA) receptor-dependent synaptic plasticity within the amygdala(1-3). Here we show that glutamatergic synaptic transmission to inhibitory interneurons in the basolateral amygdala is mediated solely by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. In contrast to AMPA receptors at inputs to pyramidal neurons, these receptors have an inwardly rectifying current-voltage relationship, indicative of a high permeability to calcium(4 5), Tetanic stimulation of inputs to interneurons caused an immediate and sustained increase in the efficacy of these synapses. This potentiation required a rise in postsynaptic calcium, but was independent of NMDA receptor activation. The potentiation of excitatory inputs to interneurons was reflected as an increase in the amplitude of the GABAA-mediated inhibitory synaptic current in pyramidal neurons. These results demonstrate that excitatory synapses onto interneurons within a fear conditioning circuit show NMDA-receptor independent long-term potentiation. This plasticity might underlie the increased synchronization of activity between neurons in the basolateral amygdala after fear conditioning(6).